Topics:

• FOCUS and SQL Similarities
• The TABLEF Command
• Creating Tables Using the HOLD Command
• Using the Dynamic JOIN Command
• Controlling Outer Join Optimization
• Missing Rows of Data in Cross-referenced Tables
• JOIN Utilities
• Implementing Search Limits
• Array Blocking for SELECT Requests
• Multiple Retrieval Paths

Using a relational adapter, you can create graphs with GRAPH requests, design interactive procedures with Dialogue Manager, or extract data from reports with the HOLD command. However, of all the facilities the adapter makes available to you for reading, retrieving, and organizing data from RDBMS tables, the most widely used is the Report Writer, invoked by the TABLE, TABLEF, and MATCH commands. Some reporting features for the adapter vary from standard FOCUS. These minor variations are discussed in this chapter. This chapter includes:

• Improving retrieval performance with the TABLEF command.
• Creating RDBMS tables from a TABLE request.
• Joined structures for reporting purposes. How multi-table Master Files compare with dynamically-joined structures, the JOIN command for unique and non-unique relationships, and the multi-field JOIN command.
• The SET ALL command and multi-table structures. How short retrieval paths affect report results.
• The join utilities CHECK FILE, ? JOIN, and JOIN CLEAR.
• Specifying search limits with the READLIMIT and RECORDLIMIT.
• For multi-table structures only, multiple retrieval paths and how sort phrases and screening conditions affect retrieval.

If you are not familiar with FOCUS syntax, you can create report requests with TableTalk, a menu-driven report generator.